Reported speech is used to report what someone else has said and involves changing the tense of the original statement. For example, direct speech would be "I'm going to the cinema" while reported speech is "He said he was going to the cinema." Verb tenses in reported speech are typically changed to the past tense. The document provides a chart showing how common verb tenses such as present simple change to past simple in reported speech, and includes examples of other verb forms like will changing to would. Time and place references are also changed in reported speech, such as now becoming then.